To do that, you will need
I do not need this.
everyone to use only one address for all their coins and nobody is doing that.
We are counting addresses balances, not users balances
Why would I put all my coins in one big bag and advertise to the world that I am filthy rich?
Why not? There are a lot of people here and there who is proud to tell everybody about his money
It would be stupid, because you would be painting a target on your back for hackers and thieves to hunt you down.
But it is funny!
Let's say somewhere in the future, some steroid induced super computer,
finds a way to encrypt private keys, which addresses would you think, will they be going for?
Ask this question to a fantast writer.